Jesus shows no disrespect, but showed love to everyone—also his family. Yet he did not want his work in the kingdom of God to give way to family ties (see Matthew 10:37).
Jesus’ mention of not only his brothers but also Mary gives this event more weight. The saying must have been hard for him, for he loved his mother, but his kingdom work was at stake. Jesus here hints at the community of the new covenant, of which he would say more (Matthew 16:18).
No, there is no lack of respect in his words. He showed love to everyone, including his family. Yet he wanted to dispel any notion that his work in the kingdom of God should give way to family ties (see Matthew 10:37).1
In fact, the fact that Jesus mentions not only his brothers but also Mary gives this event particular weight. The saying must have been painful for him, for we know that he deeply loved his mother. But there were higher things at stake at the time. In this statement by Jesus we see, in principle, the beginning of the community of the new covenant, of which Jesus would later speak expressly in Matthew 16:18.2
48 But he replied to the man who told him, “Who is my mother, and who are my brothers?”